<?php
/**
 * PHPExcel
 *
 * Copyright (c) 2006 - 2010 PHPExcel
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * @category   PHPExcel
 * @package    Shared
 * @copyright  Copyright (c) 2006 - 2010 PHPExcel (http://www.codeplex.com/PHPExcel)
 * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
 * @version    1.7.3c, 2010-06-01
 */


/**
 * Shared_String
 *
 * @category   PHPExcel
 * @package    Shared
 * @copyright  Copyright (c) 2006 - 2010 PHPExcel (http://www.codeplex.com/PHPExcel)
 */
class Shared_String
{
        /**     Constants                               */
        /**     Regular Expressions             */
        //      Fraction
        const STRING_REGEXP_FRACTION    = '(-?)(\d+)\s+(\d+\/\d+)';


        /**
         * Control characters array
         *
         * @var string[]
         */
        private static $_controlCharacters = array();

        /**
         * SYLK Characters array
         *
         * $var array
         */
        private static $_SYLKCharacters = array();

        /**
         * Decimal separator
         *
         * @var string
         */
        private static $_decimalSeparator;

        /**
         * Thousands separator
         *
         * @var string
         */
        private static $_thousandsSeparator;

        /**
         * Is mbstring extension avalable?
         *
         * @var boolean
         */
        private static $_isMbstringEnabled;

        /**
         * Is iconv extension avalable?
         *
         * @var boolean
         */
        private static $_isIconvEnabled;

        /**
         * Build control characters array
         */
        private static function _buildControlCharacters() {
                for ($i = 0; $i <= 31; ++$i) {
                        if ($i != 9 && $i != 10 && $i != 13) {
                                $find = '_x' . sprintf('%04s' , strtoupper(dechex($i))) . '_';
                                $replace = chr($i);
                                self::$_controlCharacters[$find] = $replace;
                        }
                }
        }

        /**
         * Build SYLK characters array
         */
        private static function _buildSYLKCharacters()
        {
                self::$_SYLKCharacters = array(
                        "\x1B 0"  => chr(0),
                        "\x1B 1"  => chr(1),
                        "\x1B 2"  => chr(2),
                        "\x1B 3"  => chr(3),
                        "\x1B 4"  => chr(4),
                        "\x1B 5"  => chr(5),
                        "\x1B 6"  => chr(6),
                        "\x1B 7"  => chr(7),
                        "\x1B 8"  => chr(8),
                        "\x1B 9"  => chr(9),
                        "\x1B :"  => chr(10),
                        "\x1B ;"  => chr(11),
                        "\x1B <"  => chr(12),
                        "\x1B :"  => chr(13),
                        "\x1B >"  => chr(14),
                        "\x1B ?"  => chr(15),
                        "\x1B!0"  => chr(16),
                        "\x1B!1"  => chr(17),
                        "\x1B!2"  => chr(18),
                        "\x1B!3"  => chr(19),
                        "\x1B!4"  => chr(20),
                        "\x1B!5"  => chr(21),
                        "\x1B!6"  => chr(22),
                        "\x1B!7"  => chr(23),
                        "\x1B!8"  => chr(24),
                        "\x1B!9"  => chr(25),
                        "\x1B!:"  => chr(26),
                        "\x1B!;"  => chr(27),
                        "\x1B!<"  => chr(28),
                        "\x1B!="  => chr(29),
                        "\x1B!>"  => chr(30),
                        "\x1B!?"  => chr(31),
                        "\x1B'?"  => chr(127),
                        "\x1B(0"  => '€', // 128 in CP1252
                        "\x1B(2"  => '‚', // 130 in CP1252
                        "\x1B(3"  => 'ƒ', // 131 in CP1252
                        "\x1B(4"  => '„', // 132 in CP1252
                        "\x1B(5"  => '…', // 133 in CP1252
                        "\x1B(6"  => '†', // 134 in CP1252
                        "\x1B(7"  => '‡', // 135 in CP1252
                        "\x1B(8"  => 'ˆ', // 136 in CP1252
                        "\x1B(9"  => '‰', // 137 in CP1252
                        "\x1B(:"  => 'Š', // 138 in CP1252
                        "\x1B(;"  => '‹', // 139 in CP1252
                        "\x1BNj"  => 'Œ', // 140 in CP1252
                        "\x1B(>"  => 'Ž', // 142 in CP1252
                        "\x1B)1"  => '‘', // 145 in CP1252
                        "\x1B)2"  => '’', // 146 in CP1252
                        "\x1B)3"  => '“', // 147 in CP1252
                        "\x1B)4"  => '”', // 148 in CP1252
                        "\x1B)5"  => '•', // 149 in CP1252
                        "\x1B)6"  => '–', // 150 in CP1252
                        "\x1B)7"  => '—', // 151 in CP1252
                        "\x1B)8"  => '˜', // 152 in CP1252
                        "\x1B)9"  => '™', // 153 in CP1252
                        "\x1B):"  => 'š', // 154 in CP1252
                        "\x1B);"  => '›', // 155 in CP1252
                        "\x1BNz"  => 'œ', // 156 in CP1252
                        "\x1B)>"  => 'ž', // 158 in CP1252
                        "\x1B)?"  => 'Ÿ', // 159 in CP1252
                        "\x1B*0"  => ' ', // 160 in CP1252
                        "\x1BN!"  => '¡', // 161 in CP1252
                        "\x1BN\"" => '¢', // 162 in CP1252
                        "\x1BN#"  => '£', // 163 in CP1252
                        "\x1BN("  => '¤', // 164 in CP1252
                        "\x1BN%"  => '¥', // 165 in CP1252
                        "\x1B*6"  => '¦', // 166 in CP1252
                        "\x1BN'"  => '§', // 167 in CP1252
                        "\x1BNH " => '¨', // 168 in CP1252
                        "\x1BNS"  => '©', // 169 in CP1252
                        "\x1BNc"  => 'ª', // 170 in CP1252
                        "\x1BN+"  => '«', // 171 in CP1252
                        "\x1B*<"  => '¬', // 172 in CP1252
                        "\x1B*="  => '­', // 173 in CP1252
                        "\x1BNR"  => '®', // 174 in CP1252
                        "\x1B*?"  => '¯', // 175 in CP1252
                        "\x1BN0"  => '°', // 176 in CP1252
                        "\x1BN1"  => '±', // 177 in CP1252
                        "\x1BN2"  => '²', // 178 in CP1252
                        "\x1BN3"  => '³', // 179 in CP1252
                        "\x1BNB " => '´', // 180 in CP1252
                        "\x1BN5"  => 'µ', // 181 in CP1252
                        "\x1BN6"  => '¶', // 182 in CP1252
                        "\x1BN7"  => '·', // 183 in CP1252
                        "\x1B+8"  => '¸', // 184 in CP1252
                        "\x1BNQ"  => '¹', // 185 in CP1252
                        "\x1BNk"  => 'º', // 186 in CP1252
                        "\x1BN;"  => '»', // 187 in CP1252
                        "\x1BN<"  => '¼', // 188 in CP1252
                        "\x1BN="  => '½', // 189 in CP1252
                        "\x1BN>"  => '¾', // 190 in CP1252
                        "\x1BN?"  => '¿', // 191 in CP1252
                        "\x1BNAA" => 'À', // 192 in CP1252
                        "\x1BNBA" => 'Á', // 193 in CP1252
                        "\x1BNCA" => 'Â', // 194 in CP1252
                        "\x1BNDA" => 'Ã', // 195 in CP1252
                        "\x1BNHA" => 'Ä', // 196 in CP1252
                        "\x1BNJA" => 'Å', // 197 in CP1252
                        "\x1BNa"  => 'Æ', // 198 in CP1252
                        "\x1BNKC" => 'Ç', // 199 in CP1252
                        "\x1BNAE" => 'È', // 200 in CP1252
                        "\x1BNBE" => 'É', // 201 in CP1252
                        "\x1BNCE" => 'Ê', // 202 in CP1252
                        "\x1BNHE" => 'Ë', // 203 in CP1252
                        "\x1BNAI" => 'Ì', // 204 in CP1252
                        "\x1BNBI" => 'Í', // 205 in CP1252
                        "\x1BNCI" => 'Î', // 206 in CP1252
                        "\x1BNHI" => 'Ï', // 207 in CP1252
                        "\x1BNb"  => 'Ð', // 208 in CP1252
                        "\x1BNDN" => 'Ñ', // 209 in CP1252
                        "\x1BNAO" => 'Ò', // 210 in CP1252
                        "\x1BNBO" => 'Ó', // 211 in CP1252
                        "\x1BNCO" => 'Ô', // 212 in CP1252
                        "\x1BNDO" => 'Õ', // 213 in CP1252
                        "\x1BNHO" => 'Ö', // 214 in CP1252
                        "\x1B-7"  => '×', // 215 in CP1252
                        "\x1BNi"  => 'Ø', // 216 in CP1252
                        "\x1BNAU" => 'Ù', // 217 in CP1252
                        "\x1BNBU" => 'Ú', // 218 in CP1252
                        "\x1BNCU" => 'Û', // 219 in CP1252
                        "\x1BNHU" => 'Ü', // 220 in CP1252
                        "\x1B-="  => 'Ý', // 221 in CP1252
                        "\x1BNl"  => 'Þ', // 222 in CP1252
                        "\x1BN{"  => 'ß', // 223 in CP1252
                        "\x1BNAa" => 'à', // 224 in CP1252
                        "\x1BNBa" => 'á', // 225 in CP1252
                        "\x1BNCa" => 'â', // 226 in CP1252
                        "\x1BNDa" => 'ã', // 227 in CP1252
                        "\x1BNHa" => 'ä', // 228 in CP1252
                        "\x1BNJa" => 'å', // 229 in CP1252
                        "\x1BNq"  => 'æ', // 230 in CP1252
                        "\x1BNKc" => 'ç', // 231 in CP1252
                        "\x1BNAe" => 'è', // 232 in CP1252
                        "\x1BNBe" => 'é', // 233 in CP1252
                        "\x1BNCe" => 'ê', // 234 in CP1252
                        "\x1BNHe" => 'ë', // 235 in CP1252
                        "\x1BNAi" => 'ì', // 236 in CP1252
                        "\x1BNBi" => 'í', // 237 in CP1252
                        "\x1BNCi" => 'î', // 238 in CP1252
                        "\x1BNHi" => 'ï', // 239 in CP1252
                        "\x1BNs"  => 'ð', // 240 in CP1252
                        "\x1BNDn" => 'ñ', // 241 in CP1252
                        "\x1BNAo" => 'ò', // 242 in CP1252
                        "\x1BNBo" => 'ó', // 243 in CP1252
                        "\x1BNCo" => 'ô', // 244 in CP1252
                        "\x1BNDo" => 'õ', // 245 in CP1252
                        "\x1BNHo" => 'ö', // 246 in CP1252
                        "\x1B/7"  => '÷', // 247 in CP1252
                        "\x1BNy"  => 'ø', // 248 in CP1252
                        "\x1BNAu" => 'ù', // 249 in CP1252
                        "\x1BNBu" => 'ú', // 250 in CP1252
                        "\x1BNCu" => 'û', // 251 in CP1252
                        "\x1BNHu" => 'ü', // 252 in CP1252
                        "\x1B/="  => 'ý', // 253 in CP1252
                        "\x1BN|"  => 'þ', // 254 in CP1252
                        "\x1BNHy" => 'ÿ', // 255 in CP1252
                );
        }

        /**
         * Get whether mbstring extension is available
         *
         * @return boolean
         */
        public static function getIsMbstringEnabled()
        {
                if (isset(self::$_isMbstringEnabled)) {
                        return self::$_isMbstringEnabled;
                }

                self::$_isMbstringEnabled = function_exists('mb_convert_encoding') ?
                        true : false;

                return self::$_isMbstringEnabled;
        }

        /**
         * Get whether iconv extension is available
         *
         * @return boolean
         */
        public static function getIsIconvEnabled()
        {
                if (isset(self::$_isIconvEnabled)) {
                        return self::$_isIconvEnabled;
                }

                // Fail if iconv doesn't exist
                if (!function_exists('iconv')) {
                        self::$_isIconvEnabled = false;
                        return false;
                }

                // Sometimes iconv is not working, and e.g. iconv('UTF-8', 'UTF-16LE', 'x') just returns false,
                if (!@iconv('UTF-8', 'UTF-16LE', 'x')) {
                        self::$_isIconvEnabled = false;
                        return false;
                }

                // Sometimes iconv_substr('A', 0, 1, 'UTF-8') just returns false in PHP 5.2.0
                // we cannot use iconv in that case either (http://bugs.php.net/bug.php?id=37773)
                if (!@iconv('UTF-8', 'UTF-16LE', 'x')) {
                        self::$_isIconvEnabled = false;
                        return false;
                }

                // CUSTOM: IBM AIX iconv() does not work
                if ( defined('PHP_OS') && @stristr(PHP_OS, 'AIX')
                                && defined('ICONV_IMPL') && (@strcasecmp(ICONV_IMPL, 'unknown') == 0)
                                && defined('ICONV_VERSION') && (@strcasecmp(ICONV_VERSION, 'unknown') == 0) )
                {
                        self::$_isIconvEnabled = false;
                        return false;
                }

                // If we reach here no problems were detected with iconv
                self::$_isIconvEnabled = true;
                return true;
        }

        /**
         * Convert from OpenXML escaped control character to PHP control character
         *
         * Excel 2007 team:
         * ----------------
         * That's correct, control characters are stored directly in the shared-strings table.
         * We do encode characters that cannot be represented in XML using the following escape sequence:
         * _xHHHH_ where H represents a hexadecimal character in the character's value...
         * So you could end up with something like _x0008_ in a string (either in a cell value (<v>)
         * element or in the shared string <t> element.
         *
         * @param       string  $value  Value to unescape
         * @return      string
         */
        public static function ControlCharacterOOXML2PHP($value = '') {
                if(empty(self::$_controlCharacters)) {
                        self::_buildControlCharacters();
                }

                return str_replace( array_keys(self::$_controlCharacters), array_values(self::$_controlCharacters), $value );
        }

        /**
         * Convert from PHP control character to OpenXML escaped control character
         *
         * Excel 2007 team:
         * ----------------
         * That's correct, control characters are stored directly in the shared-strings table.
         * We do encode characters that cannot be represented in XML using the following escape sequence:
         * _xHHHH_ where H represents a hexadecimal character in the character's value...
         * So you could end up with something like _x0008_ in a string (either in a cell value (<v>)
         * element or in the shared string <t> element.
         *
         * @param       string  $value  Value to escape
         * @return      string
         */
        public static function ControlCharacterPHP2OOXML($value = '') {
                if(empty(self::$_controlCharacters)) {
                        self::_buildControlCharacters();
                }

                return str_replace( array_values(self::$_controlCharacters), array_keys(self::$_controlCharacters), $value );
        }

        /**
         * Try to sanitize UTF8, stripping invalid byte sequences. Not perfect. Does not surrogate characters.
         *
         * @param string $value
         * @return string
         */
        public static function SanitizeUTF8($value)
        {
                if (self::getIsIconvEnabled()) {
                        $value = @iconv('UTF-8', 'UTF-8', $value);
                        return $value;
                }

                if (self::getIsMbstringEnabled()) {
                        $value = mb_convert_encoding($value, 'UTF-8', 'UTF-8');
                        return $value;
                }

                // else, no conversion
                return $value;
        }

        /**
         * Check if a string contains UTF8 data
         *
         * @param string $value
         * @return boolean
         */
        public static function IsUTF8($value = '') {
                return utf8_encode(utf8_decode($value)) === $value;
        }

        /**
         * Formats a numeric value as a string for output in various output writers forcing
         * point as decimal separator in case locale is other than English.
         *
         * @param mixed $value
         * @return string
         */
        public static function FormatNumber($value) {
                if (is_float($value)) {
                        return str_replace(',', '.', $value);
                }
                return (string) $value;
        }

        /**
         * Converts a UTF-8 string into BIFF8 Unicode string data (8-bit string length)
         * Writes the string using uncompressed notation, no rich text, no Asian phonetics
         * If mbstring extension is not available, ASCII is assumed, and compressed notation is used
         * although this will give wrong results for non-ASCII strings
         * see OpenOffice.org's Documentation of the Microsoft Excel File Format, sect. 2.5.3
         *
         * @param string $value UTF-8 encoded string
         * @return string
         */
        public static function UTF8toBIFF8UnicodeShort($value)
        {
                // character count
                $ln = self::CountCharacters($value, 'UTF-8');

                // option flags
                $opt = (self::getIsIconvEnabled() || self::getIsMbstringEnabled()) ?
                        0x0001 : 0x0000;

                // characters
                $chars = self::ConvertEncoding($value, 'UTF-16LE', 'UTF-8');

                $data = pack('CC', $ln, $opt) . $chars;
                return $data;
        }

        /**
         * Converts a UTF-8 string into BIFF8 Unicode string data (16-bit string length)
         * Writes the string using uncompressed notation, no rich text, no Asian phonetics
         * If mbstring extension is not available, ASCII is assumed, and compressed notation is used
         * although this will give wrong results for non-ASCII strings
         * see OpenOffice.org's Documentation of the Microsoft Excel File Format, sect. 2.5.3
         *
         * @param string $value UTF-8 encoded string
         * @return string
         */
        public static function UTF8toBIFF8UnicodeLong($value)
        {
                // character count
                $ln = self::CountCharacters($value, 'UTF-8');

                // option flags
                $opt = (self::getIsIconvEnabled() || self::getIsMbstringEnabled()) ?
                        0x0001 : 0x0000;

                // characters
                $chars = self::ConvertEncoding($value, 'UTF-16LE', 'UTF-8');

                $data = pack('vC', $ln, $opt) . $chars;
                return $data;
        }

        /**
         * Convert string from one encoding to another. First try iconv, then mbstring, or no convertion
         *
         * @param string $value
         * @param string $to Encoding to convert to, e.g. 'UTF-8'
         * @param string $from Encoding to convert from, e.g. 'UTF-16LE'
         * @return string
         */
        public static function ConvertEncoding($value, $to, $from)
        {
                if (self::getIsIconvEnabled()) {
                        $value = iconv($from, $to, $value);
                        return $value;
                }

                if (self::getIsMbstringEnabled()) {
                        $value = mb_convert_encoding($value, $to, $from);
                        return $value;
                }
                if($from == 'UTF-16LE'){
                        return self::utf16_decode($value, false);
                }else if($from == 'UTF-16BE'){
                        return self::utf16_decode($value);
                }
                // else, no conversion
                return $value;
        }
        
        /**
         * Decode UTF-16 encoded strings.
         *
         * Can handle both BOM'ed data and un-BOM'ed data.
         * Assumes Big-Endian byte order if no BOM is available.
         * This function was taken from http://php.net/manual/en/function.utf8-decode.php
         * and $bom_be parameter added.
         *
         * @param   string  $str  UTF-16 encoded data to decode.
         * @return  string  UTF-8 / ISO encoded data.
         * @access  public
         * @version 0.2 / 2010-05-13
         * @author  Rasmus Andersson {@link http://rasmusandersson.se/}
         * @author vadik56
         */
        function utf16_decode( $str, $bom_be=true ) {
                if( strlen($str) < 2 ) return $str;
                $c0 = ord($str{0});
                $c1 = ord($str{1});
                if( $c0 == 0xfe && $c1 == 0xff ) { $str = substr($str,2); }
                elseif( $c0 == 0xff && $c1 == 0xfe ) { $str = substr($str,2); $bom_be = false; }
                $len = strlen($str);
                $newstr = '';
                for($i=0;$i<$len;$i+=2) {
                        if( $bom_be ) { $val = ord($str{$i})   << 4; $val += ord($str{$i+1}); }
                        else {        $val = ord($str{$i+1}) << 4; $val += ord($str{$i}); }
                        $newstr .= ($val == 0x228) ? "\n" : chr($val);
                }
                return $newstr;
        }

        /**
         * Get character count. First try mbstring, then iconv, finally strlen
         *
         * @param string $value
         * @param string $enc Encoding
         * @return int Character count
         */
        public static function CountCharacters($value, $enc = 'UTF-8')
        {
                if (self::getIsIconvEnabled()) {
                        $count = iconv_strlen($value, $enc);
                        return $count;
                }

                if (self::getIsMbstringEnabled()) {
                        $count = mb_strlen($value, $enc);
                        return $count;
                }

                // else strlen
                $count = strlen($value);
                return $count;
        }

        /**
         * Get a substring of a UTF-8 encoded string
         *
         * @param string $pValue UTF-8 encoded string
         * @param int $start Start offset
         * @param int $length Maximum number of characters in substring
         * @return string
         */
        public static function Substring($pValue = '', $pStart = 0, $pLength = 0)
        {
                if (self::getIsIconvEnabled()) {
                        $string = iconv_substr($pValue, $pStart, $pLength, 'UTF-8');
                        return $string;
                }

                if (self::getIsMbstringEnabled()) {
                        $string = mb_substr($pValue, $pStart, $pLength, 'UTF-8');
                        return $string;
                }

                // else substr
                $string = substr($pValue, $pStart, $pLength);
                return $string;
        }


        /**
         * Identify whether a string contains a fractional numeric value,
         *    and convert it to a numeric if it is
         *
         * @param string &$operand string value to test
         * @return boolean
         */
        public static function convertToNumberIfFraction(&$operand) {
                if (preg_match('/^'.self::STRING_REGEXP_FRACTION.'$/i', $operand, $match)) {
                        $sign = ($match[1] == '-') ? '-' : '+';
                        $fractionFormula = '='.$sign.$match[2].$sign.$match[3];
                        $operand = Calculation::getInstance()->_calculateFormulaValue($fractionFormula);
                        return true;
                }
                return false;
        }       //      function convertToNumberIfFraction()

        /**
         * Get the decimal separator. If it has not yet been set explicitly, try to obtain number
         * formatting information from locale.
         *
         * @return string
         */
        public static function getDecimalSeparator()
        {
                if (!isset(self::$_decimalSeparator)) {
                        $localeconv = localeconv();
                        self::$_decimalSeparator = $localeconv['decimal_point'] != ''
                                ? $localeconv['decimal_point'] : $localeconv['mon_decimal_point'];
                                
                        if (self::$_decimalSeparator == '')
                        {
                                // Default to .
                                self::$_decimalSeparator = '.';
                        }
                }
                return self::$_decimalSeparator;
        }

        /**
         * Set the decimal separator. Only used by Style_NumberFormat::toFormattedString()
         * to format output by Writer_HTML and Writer_PDF
         *
         * @param string $pValue Character for decimal separator
         */
        public static function setDecimalSeparator($pValue = '.')
        {
                self::$_decimalSeparator = $pValue;
        }

        /**
         * Get the thousands separator. If it has not yet been set explicitly, try to obtain number
         * formatting information from locale.
         *
         * @return string
         */
        public static function getThousandsSeparator()
        {
                if (!isset(self::$_thousandsSeparator)) {
                        $localeconv = localeconv();
                        self::$_thousandsSeparator = $localeconv['thousands_sep'] != ''
                                ? $localeconv['thousands_sep'] : $localeconv['mon_thousands_sep'];
                }
                return self::$_thousandsSeparator;
        }

        /**
         * Set the thousands separator. Only used by Style_NumberFormat::toFormattedString()
         * to format output by Writer_HTML and Writer_PDF
         *
         * @param string $pValue Character for thousands separator
         */
        public static function setThousandsSeparator($pValue = ',')
        {
                self::$_thousandsSeparator = $pValue;
        }

        /**
         * Convert SYLK encoded string to UTF-8
         *
         * @param string $pValue
         * @return string UTF-8 encoded string
         */
        public static function SYLKtoUTF8($pValue = '')
        {
                // If there is no escape character in the string there is nothing to do
                if (strpos($pValue, '') === false) {
                        return $pValue;
                }

                if(empty(self::$_SYLKCharacters)) {
                        self::_buildSYLKCharacters();
                }

                foreach (self::$_SYLKCharacters as $k => $v) {
                        $pValue = str_replace($k, $v, $pValue);
                }

                return $pValue;
        }

}
